Nodes In Wireless Networks Research Articles

무선 메쉬 네트워크에서 라우터 노드 배치를 위한 타부 서치 알고리즘

ABSTRACT This paper proposes a Tabu search algorithm to maximize the connectivity between the router nodes and the client nodes in wireless mesh networks. As the number of the router nodes and the client nodes in the networks increases, the amount of calculation for finding the solution would be too much increased. To obtain the optimal solution within a reasonable computation time for a high-density network, we propose a Tabu search algorithm to obtain the optimal solution for maximizing the connectivity. In order to make a search more efficient, we propose some efficient neighborhood generating operations of the Tabu search algorithm. We evaluate those performances through some experiments in terms of the maximum number of the connectivity and the execution time of the proposed algorithm. The comparison results show that the proposed algorithm outperforms other existing algorithms. 키워드 : 무선 메쉬 네트워크, 타부 서치, 라우터 노드 배치, 최적화 Key word : Optimization, router node placement, tabu search, wireless mesh networksJournal of the Korea Institute of Information andCommunication Engineering

SIR 향상 다중 노드용 UCA 빔 형성 전력 할당 방법

본 논문에서는 원형 배열 안테나를 사용한 무선 메쉬 네트워크 LOS 환경에서 다중 노드 빔 형성을 위한 SIR 향상 빔 형성 전력 할당 기법을 제안한다. 제안된 방법은 다중 노드 접속을 위한 다중 노드 빔 형성 시 존재하는 전력 제한 조건을 만족시키며 송신 전력이 최대화되는 다중 빔 전력 할당 기법이다. 전산 모의 실험을 통하여 제안 한 빔 형성 전력 할당을 적용하였을 때 UCA 안테나에서 기존의 방법보다 다중 노드의 SIR이 향상됨을 확인하였다. This paper proposes a power allocation method for multiple node beamforming with uniform circular array antennas to increase SIR of nodes in wireless mesh network. The proposed method calculates beamforming power allocation vectors that maximizes SIR satisfied with power constraint of HPA. The simulation results demonstrate the proposed method achieves the enhanced SIR of nodes than that of beamforming method.

Implementation a method to provide quality in manet and survey the effect of that at decreasing Data Dropped of DSR and AODV routing protocols

In Ad-Hoc wireless networks nodes change their situations proximately, that means this situation requires routing protocols that have ability to adaptability with this changes. Providing the QoS in this networks is intolerable, through topology changes and use the joint media by the network nodes. The most routing protocols that designed for this networks, only find the route by the scales of step and don’t consider the QoS of created routes. In this cases for providing QoS , we decided to apply one of the methods of providing the QoS that named : resources reserve on the routing protocols. For this reason, in this essay we use two different scenarios in a MANET’s example environment, which they have (500*500)M and (1000*1000)M dimensions. The scenarios have fifty nodes. The AODV and DSR are usable routing protocols and the work styles of these protocols are like the followings: At first we implement the RSVP protocol on the mentioned routing protocols and we compare the route discovering time of them when RSVP protocol applied to when protocol have not applied. Scenarios that implemented and evaluated by Opnet 14 simulator and simulation results are fully described. Simulation results show this fact that when we apply RSVP on AODV and DSR routing protocol, route discovery time is reduced. Also AODV has a better performance.

Reinforcement based Cognitive Algorithms to Detect Malicious Node in Wireless Networks

The growth of wireless communication technologies and its applications leads to many security issues. Malicious node detection is one among the major security issues. Adoption of cognition can detect and Prevent malicious activities in the wireless networks. To achieve cognition into wireless networks, we are using reinforcement learning techniques. By using the existing reinforcement techniques, we have proposed GreedyQ cognitive (GQC) and SoftSARSA cognitive (SSC) algorithms for malicious node detection and the performances among these algorithms are evaluated and the result shows SSC algorithm is best algorithm. The proposed algorithms perform better in malicious node detection as compared to the existing algorithms.

Deployment of Sensors in WSN: An EfficientApproach Based on Dynamic Programming

Efficient sensor node deployment is extremely important in wireless sensor networks. It earns great practical meanings through using fewer sensor nodes as far as possible to satisfy different requirements such as the requirement on coverage and overcoming the potential sensor node failures and the adverse influence from the environment. We propose an efficient approach for the deployment of sensor nodes in wireless networks, termed as EDSNDA, which is excellent in taking both the requirements of sensor coverage and network connectivity into consideration when minimizing the number of necessary sensor nodes to the best of its ability. We proposed a new coverage model of sensor node. Based on the sensor coverage model, we establish four dynamic programming models in four different practical situations, respectively. The algorithms are then proposed which are used for solving the corresponding dynamic programming models. The validity of the method is justified by simulation studies in which the method is compared with the current representative methods. The simulation results show that our method performs better than the other ones with fewer sensor nodes, better coverage and network connectivity result in the same circumstance.

Probabilistic-Constrained Simultaneous Wireless Information and Power Transfer for Multiple-Relay Networks

Simultaneous Wireless Information and Power Transfer (SWIPT) potentially offers great convenience to prolong the lifetime of energy-constrained nodes in wireless networks. This paper considers multiple-relay network that incorporates SWIPT where the Base Station (BS) communicates with the user through the help of multiple single-antenna relays. A relay beamforming and energy harvest design is proposed to maximize the probability of the Signal-to-Noise-Ratio (SNR) of the user larger than a pre-defined threshold while not violating the power constraint of relays and guaranteeing the energy of the user received from probabilistic perspective. Then, we use S-lemma transform probabilistic-constrained problem into non- probability. An iteration-based algorithm is devised to solve this problem. Simulation results verify the effectiveness of the proposed scheme, which can achieve better tradeoff between the power consumption of relays and the user's SNR.

Performance improvement of rectifiers for WPT exploiting thermal energy harvesting

This paper proposes a combined harvesting system to improve the efficiency and flexibility of autonomous wireless network nodes, supplied by means of wireless power transfer technique. In particular, a mixed system for electromagnetic (EM) and thermal energy harvesting (EH), conceived for passive nodes of wireless sensor networks and radio frequency (RF) identification tags, is described. The proposed system aims at increasing the effectiveness and the efficiency of the EH system by integrating an antenna and a rectifier with a thermo-electric generator (TEG) able to perform thermal EH. The energy provided by the thermal harvester is exploited twice: to increase the rectifier efficiency by providing a voltage usable to improve the bias condition of the rectifying diode, and to provide additional dc energy, harvested for free. Ultimately, a great efficiency improvement, especially at low incident RF power, has been observed. The design methodology and the EM performance of a quarter-wavelength patch antenna, integrated with the TEG are resumed. Then, a test campaign to evaluate the thermal EH performance has been carried out. Afterward, a rectifier with variable bias voltage, operating at the same frequency of the antenna, has been opportunely designed to exploit the harvested thermal energy to bias the diode. A measurement campaign has been then carried out to test the efficiency increment obtained and to validate the proposed solution.

Improved Life of Watchdog Nodes in Ad hoc Networks

Clustering or Cluster formation of nodes in wireless networks facilitates resource reuse and increases the performance capacity of the system. This paper presents a cluster-based solution to improve life of watchdog nodes that are designed to monitor intrusions in ad hoc network. The proposed approach ensures load sharing, increased robustness, added security and high reliability such that the entire network becomes fault tolerant. Unlike the existing systems, the algorithm intends to create multiple cluster heads for each cluster, thereby balancing the monitoring nodes’ work load and reducing reelection overhead. Simulation results show the competence of the proposed work over the existing approaches in terms of performance metrics such as percentage of alive nodes, cluster head election time, re-election time, election rate and communication overhead.

Progresses in on-body channel models for wireless body area networks

On-body communication channels are a physical basis for the establishment of an effective and reliable wireless link between on-body nodes in wireless body area networks (WBANs).Due to normally strict limitations in transmit power and power consumptions of on-body nodes as well as the human-centered characteristics of WBANs,on-body channels are prone to be affected by the electromagnetic properties of human tissues,human movements,application environments and transceiver antennas,which increase greatly the complexity of the research on channel models.The paper discusses the developments,mathematical expressions and application characteristics of five types of on-body channel models,such as the simple path loss model,the hybrid path loss model,the small-scale fading model,the scenario-based model and the ultra-wideband model,and reviews the current progress on the modeling on-body channels. Key words: Wireless body area network; On-body channel; Path loss; Fading

Quantum Game Techniques Applied to Wireless Networks Communications

In order to analyze the power control problem, the wireless quantum network nodes are modeled as players at a quantum game. The power control problem is one of the most significant wireless communications challenges which characteristics make it proper to be modeled by means of game theory techniques. The problem results in non-cooperative game by nature, but, under quantum rules, a larger strategy space leads the players to choose a coalition strategy as the best option. Thus, the use of quantum game strategies makes possible the emergence of new equilibrium, which guarantees the best possible performance to the whole network. We show also that the whole network power consumption decreases when the intrinsic parallel behavior of quantum computation is capitalized. Moreover, the design of efficient medium access control algorithms is possible.

Research on Monitoring and Protection of Water Environment in Rural Areas

This article first introduces the current situation of heavy metal pollution and heavy metal detection technology, and selected the voltammetry as the principle of detection system in electrochemical stripping. At the same time, introduces the related content of wireless sensor network. According to project requirements, design a set of heavy metal functional modularity, automation instrumentation, module power supply system which can meet the applicable to different working environment; for the need wireless sensor networks, proposes a design of wireless network node; finally, in the waterway system in laboratory environment test and heavy metal concentration detection test experiments show that the instrument, this system can meet the design requirements.

A Novel Opportunistic Relay and Energy Efficient Power Allocation Algorithm in Cooperative Wireless Sensor Networks

A series of challenges exist in the process of sensor network research which can not be solved by one sensor node. Cooperative communication, based on the idea of spatial diversity, which makes different users or nodes in wireless network share their antennas or other network resources, is a promising technique toward improving performance of wireless sensor network significantly. This article adopts cooperation between nodes and opportunistic collaboration transmission strategy is proposed. Energy efficient power allocation algorithm in wireless sensor network is put forward to optimize performance of opportunistic cooperative transmission. Through the simulation, regardless of statistical feature of channel state of opportunistic node, opportunistic cooperation can effectively improve the performance of the system. Using energy efficient power allocation algorithm can effectively reduce energy consumption of the network and improve the network performance

A Physical Layer Key Negotiation Mechanism to Secure Wireless Networks

The rapid technological developments in computing technology and the proliferation of wireless network nodes with light infrastructure, have emerged large quantities of security requirements of informational privacy in cyberspace. Due to the inherent nature of open medium, diversity and variability of network topology, wireless networks are greatly difficult to secure by traditional methods. A physical layer key negotiation mechanism to secure wireless networks is proposed to quickly exchange and establish conventional cryptographic keys by exploiting the wireless channel’s characteristics. The physical layer key negotiation mechanism and its supplementary exception handling caused by the variations in communication paths are both described step by step. The simulation results verify the consistency of the keys of legitimate users, robustness and feasibility of this mechanism. Furthermore this cross-layer security technology is an exemplary complement to existing wireless network protocols to improve their security and enhances the ability to resist replay attacks, brute-force attack and eavesdropping.

Research on Data Packets Clustering Algorithm in the Wireless Multiple Hop Network

In view of the problems existing in the wireless multiple hop network such as consumption imbalance of node power, disunity of node transmission data efficiency, unfixed life within the scope of network, it has put forward the trade-off relationship between the wireless multiple hop network node energy consumption and multiple factors based on the k-means clustering method. The principle of steps and characteristics of the k-means clustering algorithm are first introduced; Then model the influence of the K-means polymerization on VoIP service quality, then use the k-means clustering method to make cluster analysis for network node data package, and mine the trade-off relationship between data transmission service quality and multiple hops node energy consumption; Finally carry on the simulation experiment to test the performance of this method. Simulation results show that the method not only improves the data transmission service quality of VoIP service, but also reduces the energy consumption of nodes and prolongs the life span of the wireless network.

Research on Wireless Sensor Networks Based on Open Source System

As the key technologies such as wireless communication, sensor continues to mature, wireless sensor networks has become a domestic and foreign focus of research in the field of wireless networks. The main work of the thesis is to implement ZigBee wireless sensor networking, using open source protocol FreakZ On the base of existing hardware. WSN hardware node consists of 32-bit microprocessor STM32F102CB based on ARM Cortex-M3 kernel and AT86RF212 radio transceiver; the software platform uses a lightweight multi-tasking operating system Contiki and open source protocol stack called FreakZ following ZigBee protocol specification, for networking wireless networks nodes. The paper presents the system architecture of WSN networking and its hardware components, software architecture and data transmission and reception processes of the networks. Using FreakZ protocol stack under the Contiki operating system on the base of the existing hardware platform, the network nodes information and topology displayed on the HyperTerminal indicates the success of WSN networking by using FreakZ protocol.

The Wireless Network Routing Protocols and Data Communication Methods for Multiple Sensor Information Used in Mining Mechanical

In view of the development of wireless sensor system data transmission model in mine mechanical, we construct a ground reflection model of double path combined with the actual background demand based on the analysis of the wireless network routing protocol. Firstly, we put forward the selection strategy on wireless communication transmission power of multiple information sensor nodes. To build a data communication mode, we proposed the selection and evaluation method of network parameters based on graph theory. In consideration of the wireless channel model, combined with the initial random layout problem of network node, we explore whether to be neighbors between any two nodes arranged at random and the constraint relationship of wireless communication distance between nodes. Finally, we make up a dynamic routing selection algorithm with a view to dynamic nodes, and conduct the simulation analysis and experiment design. The research results show that with the increase of the random movement speed about network nodes, the process of depleting the energy of the nodes in the wireless sensor network speeds up, which explain the protocol given in the paper requires more energy to cope with the problem that the network topology changes frequently because of the random motion of nodes in network. The research results provide a reference to the wireless network node research and design in the electromechanical integration design.

OPTIMIZING THE DATA TRANSMISSION BETWEEN MULTIPLE NODES DURING LINK FAILURE IN WIRELESS NETWORK

The nodes in wireless network are mobile resulting in dynamic topology with high rate of link breakage and network partitions leading to interruptions in the ongoing communication in contrast to wired network. In the networks the link failure may be occurred due to a loss of energy in nodes, congestion, and power loss in nodes. Routing techniques help in path establishment for transmission. The existing routing protocols suffer from overhead causing energy loss which may be further aggravated by link failures. Different techniques can be used to prevent one path failure and this system uses multipath routing to overcome this issue. In this technique the system uses network coding protection for both single and multiple link failures. The system states that in connection each node receives a multiple copies of same data, first copy from the primary path and second copy from secondary path. In order to improve the performance, data is to be transmitted through the secondary path is compressed using Huffman coding in order to save the energy consumption. And encoding mechanism is used for providing security for the data transmitted between source to destination. This will ensure the recovery of data in failure of working path.

Partition and Cooperation for Crowded Multi-rate WLANs

Recently, growth in smart devices has increased along with the number of wireless nodes in wireless local area networks (WLANs). The increased number of nodes causes throughput degradation due to f...

Throughput and Delay Analysis of IEEE 802.11 DCF in the Presence of Hidden Nodes for Multi-hop Wireless Networks

Hidden node collision in a contention-based medium access control protocol contributes to poor wireless network performance. This paper extended the Bianchi's study and introduces a mathematical model that can be used to calculate throughput and delay for the IEEE 802.11 distributed coordination function of a multihop wireless network infrastructure assuming the presence of hidden node collision. This research investigates three essential parameters of multi-hop wireless networks. More specifically, this paper aims to analyze the effect of hidden nodes, network size, and maximum backoff stage on the overall system throughput and packet delay. Results clearly reveal the effect of large wireless network size, maximum backoff stage, and collision probability on throughput and packet delay. On one hand, throughput does not depend on the maximum backoff stage (m) for a small network size (e.g., n $$=$$ = 10). On the other hand, throughput does not strongly depend on the number of nodes when the backoff stage values are high. Comparing our proposed model in case single-hop with the Bianchi model, the analysis results indicate that the throughput values in our model when the numbers of nodes are 10, 50, and 100 are 0.6031, 0.4172 and 0.3433 respectively; whereas the throughput values are respectively 0.8370, 0.8317 and 0.8255 at the same number of nodes for the Bianchi model. The difference can be attributed to several assumptions made in our proposed model that were not considered in the Bianchi model.

A game theoretic approach to detect and co-exist with malicious nodes in wireless networks

Identification and isolation of malicious nodes in a distributed system is a challenging problem. This problem is further aggravated in a wireless network because the unreliable channel hides the actions of each node from one another. Therefore, a regular node can only construct a belief about a malicious node through monitoring and observation. In this paper, we use game theory to study the interactions between regular and malicious nodes in a wireless network. We model the malicious node detection process as a Bayesian game with imperfect information and show that a mixed strategy perfect Bayesian Nash Equilibrium (also a sequential equilibrium) is attainable. While the equilibrium in the detection game ensures the identification of the malicious nodes, we argue that it might not be profitable to isolate the malicious nodes upon detection. As a matter of fact, malicious nodes can co-exist with regular nodes as long as the destruction they bring is less than the contribution they make. To show how we can utilize the malicious nodes, a post-detection game between the malicious and regular nodes is formalized. Solution to this game shows the existence of a subgame perfect Nash Equilibrium and reveals the conditions that are necessary to achieve the equilibrium. Further, we show how a malicious node can construct a belief about the belief held by a regular node. By employing the belief about the belief system, a Markov Perfect Bayes–Nash Equilibrium is reached and the equilibrium postpones the detection of the malicious node. Simulation results and their discussions are provided to illustrate the properties of the derived equilibria. The integration of the detection game and the post-detection is also studied and it is shown that the former one can transit into the latter one when the malicious node actively adjusts its strategies.